Time switch circuit arrangement



smug@ f 5 3 d u.. :a

`Filed April 18, 1958 HL 1A. M. JACOBS HTM, TIM'swITcH CIRCUITARRANGEMENT eNvE'n-Dw HENR JOSEPH ANTONIUS MARIE JACOBS LEONARDUS'FRANSISCUS VAN WEUDEVEN @tra incrire t :EM cdi/'WITCH 'CIRCUITRRANIGEMEN'II" llllenri .lloseph Antonius Marie-.llacobs 'sindVLeonardus Fransiscns van de Weijdeven, both of lEindhoven,`

This invention relates to time switches comprising a ser. ne. 729,4@

controllable gas-filled or vapour-filled dischargetube fed via aresistor from a direct-current source and in whichV a charged capacitoris' included as a negativebiassig voltage 1n the grid circuit ofthedischarge tube, at least part of its period of discharge to the momentVof igni` tion of the discharge tube being decisive for the"desiredperiod of time. Such a time switchmay be used for severalpurposes, but is important more particularlyV for the control of twogas-filled or vapour-titled' main dis- NAY., a corporation ot Dell-:1

Netherlands May-8, i957.

charge tubes connected in anti-parallel (either directlyv or through oneor more auxiliary discharge tubes) for resistance welding.

According to the invention, a resistor is included between the junctionof the cathode withthe capacitor and the positive terminal and a switchis included between said junction and the negative terminal, the gridbeing connected to a tapping point, preferably adjustable, on apotentiometer included between the positive andthe negative terminal. I

The desired period of tim of the passage of current through the switchupon closure thereof and the moment when thev discharge tube is ignitedaf-ter the capacitor has sulciently discharged.

Such a' time s witch may operate either synchronously or asynchronouslywith regard to theualternating supply voltage for the said maindischargetubes." In the former case, the switch between the cathode andthenegativ'e terminal may comprise a controllabledischarge'tube,v

the control of which is synchronized with said alternat-v ing voltage,whereas, in the second case,the switch may comprise a manually-operatedmechanical switch or a relay.4

.According to a further feature of theinvention, a resistor is includedbetween the 'grid and' the tapping point on the potentiometer, whichresistor is preferably .bridged by a rectifier, the anode of whichisgconnectcd to the grid. The resistor serves as a discharge resistor eis determined by themornent.

f'or the capacitor, the presence of the rectifier permitting rapidrecharging of the capacitor.-

In order that the invention may be lreadily carried l into effect, itwill now bedescribed more fully, byway of example, with reference to theaccompanying drawing.

FIG. l shows a controllable gas-lle d or vapour-filled discharge tube 1having its anode connected via a resistor 2 to the positive terminal ofa direct voltage source 3. The grid circuit of tube ll includes acapacitor 4., of which the junction 5 with the cathode is connected viaa resistor u to the positive terminal, on the one hand, and via a switch"i to the negativel terminal, on the other. The grid is also connectedto a ytapping point 8 on a potentiometer 9, included between thepositive and the negative'terminal As soon as the'direct voltage source3 has been con nected into circuit, the capacitor` t with the switch 7opel. will be charged via resistor 6 and the lower portion otpotentiometer 9 to the voltage of the. positive terminal decreased bythe voltage on the tapping point d, sothat the grid of tube ll has anegative biassing'potential. The voltage at capacitor l is representedby ll0 inFIG.v2, in which the positive and negative terminals areindicated by i l t5- and Furthermore, in FIG. 2, the'positive voltageThe disadvantage may 'This fates.

iidlhllid Patented Sept. i9, 'Bigdil at the anode is indicated by lilland the voltage at the .cathode of tube l is indicated by l2.

When switch 7 is closed point I3 at the cathode in lFIG. l suddenlybecomes negative due to the connection discharged to an extent such thattube l. is ignited, as

represented by the line i9. Consequently, the positive voltage at theanode of ,tube lt decreases, for example, to the value 2G', which is atthe same time the voltage at theoutput terminal 2l in FIG, l. Variationsin potential thus occur at the terminals liti and 2i. with an inter-Yval as represented by the line 22 in FIG. 2, which variations may serveas control pulses for determining a desired period of time, for examplethe welding time forwelding tools. .The moment oi ignition of tube ll ati8 may be determined more accurately if peak voltages (for example froma saturated transformer) are superimposed on the voltage 17 of capacitord.

In the case described, the :desired period'of time is dependent upon theadjustmentof the tapping point (i on the potentiometer 9, by which thevoltage llt) of capacitor 4 is determined, and upon the value of thelowel portionlot= potentiometer 9,. throughlwhich the capacitol isdischarged, and hence also upon the adjustment ot tapping point 3. Thisis objectionable in many cases.

be vovercome'by providing a separate resistor between. the Vpoints 23and 2d in FIG. 1, so that thetime olt discharge 22 is less dependentupon the adjustment of the tapping point 8.

It isfrequently desirable that, immediately after expiration .of 'theperiod of time 22, the circuit should again be ready for a subsequentswitching manipulation. For this purpose, the capacitor; t must rst bere-charged. up a certain time 'more particularly in the presence of aresi stor between the points 23' and 24, which is usually comparativelyhigh-ohmic as compared to the resistor 6 and the lower portion ofpotentiometer 9.

In order to overcome this disadvantage, the resistor 25 (sea. FIG. 3)between the points 23 and 2d may be bridged by a rectifier 26, 'theanode of which is con nected to the grid, so that upon re-charging ofcapacitor'i, the .resistor 25 is short-.circuited and a rapid charge isthus rendered possible.

In certain cases, aplurality oiA switching manipula- 'tions insuccession are desired wlthout any interruption,

for example with resistance-welding tools, for which a certain durationof the electrode pressure prior to welding; of the welding process and acertain duration of the electrode pressure after welding are desired.

In such cases. the switch, l of FIG. l may be replaced tion of theelectrode pressure and of 'the welding time,

as indicated by28 .and Z9.r espective ly in FIG'. 5.

I-n a similari manner, the switch '7' of FIG. 4 may be replaced by athird timey switchas shown inFIG. l.

A simple. automatic switch to replace the switch 7, '7y

-or the corresponding switch v7" (not shown) in the said third timeswitch may be Constltuted by a flip-ilop circuit is thus positive,

, .certain time* after .cathode and ai contr'Ol..

tive polarity terminals,fsd second potentiometer f Erneans, yineai'is yfor deriving a i l the anode of said second discharge device, and meansfor deriving rst-m'entioned discharge device;

as shown inlliIG'i '6,-it 'being possible for the whole circuit vto bedesignedy for only one work program or for repeated performance.'

Instead .ofthe switch 7", which is not show n, -a gasfilled'dischargetnbe Sois arranged in flip-hop connection with ,7a. tube Slhbyme.an`s of. a common cathode resistor 32, a'capa'citor 33"and anoderesistors. and'SS. One output terminal 14"'isc6nnected to-the' anode ofTube y31, normally, `is conducting, for example by means' of an ignitionpulsesupplied'at the arrow 36,' .The

Y. .ia-naw,- tuuese is ignited lat s?, the Avoltage-.at llt-"decreasesandtubeM extinguishes. The tube I'f lis lignited after soineft-ime',subsequently tube l' ignited-.2

potentiometer havingsa tapping point'thereon connected to said grid, asecond resistor connected to said positive polarity terminal, acapacitor for applying a negative biasing potential Ato said gridconnected in serics between Vsaid second resistorv and the'said grid,means connecting .a point in said series connection common to saidsecond resistor andsaid capacitor to said cathode, a second .electrondischarge device having an anode, a cathode and a control grid, meansconnectingthe anode of said second -discharge device to said commonpoint, a third resistor4 Y connecting the anode of saidsecond dischargedevice to i connected between said' terminals, said second 15 is'ignitedandv thenlalsojaftersome time, tube 1 is Due .to the .ignitioiiof tubeJl, a voltage'pulse is suppliedfroriithe grid via a .capacitor 38 to thegrid'of A vtubeSiL resultingin this tube being ignited and tube 3 0extinguishing. The initial condition is then restoredv again. f ACOD'OI. fthe' electrode pressure, the welding time and ltheafter-pressure `of the electrodes is indicated -dia-vgrammaticallybyj23y29 andiitv in FIG, 7. j

When arepetitiorigofthis program is desired, 'an out- -put terminal 40ctthe anodel of tube 31 maybe connected viaa time delay'lilfltogthecoii'trol of tube tl'so that a expiration o i-the pulse 2lin FIG. 7, the pulseilft'zf-is Iagain*produced by ignition of tube 30.30

electron; discharg'odvice having ananode, a 'cathode-and havinga'posit'ivepolarityterminal and a negative polar-A ity 'terni'inah a,first "resistorf- 'said' positive po-l'a'rit-y{.,termiiial, v

connecting said-anode to a potentiometer connected lbetweensaidposit-ive,andv negative `polarity terminals, said potentiometer--having agt'apping point thereon con-v .neetedto saidk grid,

second' resistor connected lto' said positive polarity terininal,1.a'vcapacitor for applying va negative biasingpoten'tial tosad gridlconnectedl in series charge device, aV fourth said fourth resistor andsaid positive polarity terminal, a second potentiometer positive andnegative polarity potentiometer having a tapping to the grid of saidsecond disresistor connected to said positive polarity terminal,a-second capacitor for' applying a negative biasing potential to thegrid of said seconddischarge device connected in series between saidfourthA resistor and said grid of said second discharge devicemeansconnecting a point in `said'seriesconnection common to point thereonconnected odeof-said second discharge device, a third electron dischargedevice havingan anode, a cathode and a control grid, means connectingthe anode ofv said third discharge device `to saidk last-'mentionedcommon point, anfth resistor connecting the anode of said thirddischarge device to said positive polarity terminal, a thirdpotentiometer connected between saidpositive and negative. polarity.terminals, said third potentiometer having a tapping point thereonconnectedto the 4grid of said third discharge device, a sixth' resistorconnected to grid of said third discharge device, means connecting apointin said series connection common to said sixth resistor and saidthird capacitor 4Q" tween said last-mentioned-common to the cathode ofsaid third discharge device, switching means connected bepoint and saidnegative polarity terminal, means, for -deriving a ir'st output voltagefroml said switching means, means for deriving a second outputvoltagefrom the anode of said third disa. third resistor connecting-theranode'of said second discharge'device 4tojsaid` positive polarityterminal, a second potentiometer connected-between said positive and.negaliaving altap'ping' point: thereon'conn'ected to the of saidsecond'discharge device; a fourth resistor .connected to said positivepolarity terminal, a second capacitor` for` applying 'afnegatiie biasing'potential to the'gridof said second dis'hasgdevice connected in seriesbetween said vifolirth -resistor 'and said grid t device; meansconn'ectinga point in saidserie's connection common to said-'fourthresistor and said second ca- -of said second ,discharge pacitor to. theAcat hod e, o' f said lsecond discharge device,

switching -means connected' between said last-mentioned 'common pointand said ynegative 'polarity terminal, means for v deriving a`iiistqo'utpu-t voltage from said switching second output voltage fromavthrd output voltgefrom the anode of said v 2. -A'tiine switch lcircuitarrangement comprising. an

forgsupplying a direct voltage terminaland a negative polarpositivepolarity'. terminal, a potentiometer connected be tween said positiveand negative polarity terminals, said tofsaid grid, a second chargedevice, means for deriving a third output .voltage from the anodeof saidsecond discharge device, and means for deriving a fourth output voltagefromA the vanodeofsa'id yinst-mentioned discharge device.

-3. A timejswitch circuit arrangement comprising an electron discharge.device having an anode,a cathode and a control grid, means forsupplying a direct voltage having a positive polarity terminal and anegative polar- .ity terminal, a first resistor connecting said anode tosaid positive polarity terminal, a potentiometer connected be- '--twecnsaid positiveand negative polarity terminals, said potentiometer havinga tapping point thereon connected biasing potential to said gridconnected in series between said second resistor and the said grid,means connecting a point in said series connection common to said secondresistor and said capacitor to said cathode, a second electron dischargedevice having an anode, a'cathode and a control grid, means connectingthe anode of said second discharge device to said common point, a third'resistor connecting the anode of said second discharge device to saidpositivepolarity terminal, a second potentiometer connected between saidpositive and negative polarity terminals, said second potentiometerhavingV a tapping 'point thereon connected to the grid charge device, ative polarity terminal, a second capacitor for lapplying a of saidsecond disnegative biasing potential to the grid of said seconddischarge device connected in series between said fourth resistor andsaid grid of said second discharge device,

means connecting a point in said series connection comsaid secondcapacitor to the cath.

connected in series .between said sixth resistor 'and said iresistorconnected Ato said positive polarity terminal, a capacitor -forapplying a negative fourth resistor connected to said posi-v 'I inon tosaid fourth resistor tapping poiritthereon thecathode or said second'vdischarged'evice, ajtliird elec. tron discharge device having 4"ananode, a 'cathode andy a control grid, means connecting the anode ofsaid third discharge device to said last mcntioned common point, afifth., resistor connecting the anode'of said third dis-vv charge deviceto said positive. .p potentiometer connecting and: said Second capacitortoV of said third discharge device to said last-mentioned common point,a fifth resistorconnecting the anode of said third discharge device tosaid positive polarity' terminal,

a third potentiometer connected between said positive and negativepolarity terminals, said third potentiometer having a tapping pointthereon connected to the grid of 'clarity terminal, a third betwecnsaidpositive andnegative polarity terminals, said-third .potentiometerhaving a tapping point thereon connected to the grid of said` thirddischarge device, a sixth resistor lconnected to said positive polarityterminal,` afthirdl capacitor for applying a4 negative biasing potential`to the grid of said third discharge d evice connected liniseriesbetween, said sixth resistor `and said gridof said third dischargedevice, means connecting a poi v cathode of said thirdI dischargedevice, switching means connected between said last-.mentioned commonpoint and saidnegativc polarity terminal, said switching meanscomprising fourth andl fifth electron discharge devices Veach having ananode, a cathode ,and a control grid conf voltage fromthe anode of `said' 'iirst-mentioned discharge' device.

4.#A ntime switch circuit arrangement comprising any electron dischargedevice having a'nar'iode, a cathode and a. control grid, means forsupplying a direct voltage havterminal and a negative lpolarity dconnecting said anodeto said positive. polarity terminal, apotentiometer-connected be ing a positive polarity terminal, l a iirstresistor rit in said series connection com- Y ifo:

"said" lpositive polarity terminal,

sixth resistor and said said third discharge device, a sixth resistorconnected to a third capacitor for applying a negative biasing potentialto the grid of said third discharge device connected `in series betweensaid grid of said third discharge device,

means connectingia point in said series connection'commonto said sixthresistor and said third capacitor to thecathode of Ssaid third dischargedevice, switching means v connected between said last-mentioned commonpoint i mon to 'said sixth resistor'and said third capacitor tothe.

andv said negativepolarity terminal, saidtswi'tching means comprisingfourth` and fth electron discharge devices each having an anode, acathode and a control grid conoutput voltage from the anode of saidrthird dischargel device'rneans for deriving tween said positive andnegative polarity. terminals,=said potentiometer 'having a tapping Vtosaid grid, a second resistor connected to said positive I a capacitorvfor applying a negative polarity terminal, biasing; potential to saidgrid connected iii series between said second resistor' and thesaid-grid, means connecting va point in said series connection common tosaid second resistoraiid said capacitor to said cathode, a second'elecpoint `thereon connected,

f for deriving a fourthoutput voltage 1 said firstrnentioned dischargedevice.

-to ,said positive nected Lin flip-op circuit arrangement with eachother,

a delay circuit, means coupling'the anode of said fifth discharge deviceto the grid'of said fourth discharge t devicemeans connecting the anodeof said fourth discharge device to` the cathode of saidl third discharge'device-and means connectingthe grid of said fifth discharge device tothe grid of said first-mentioned dis` 'v charge device, means forderiving a first output voltage troni said switching means, means forderiving a second the anode of said second discharge device, and meansAVV timel switch circuitarrangement comprising atl electrondischargedevice having :in anode, a cathode and v l:havingapo'sitive'polarity'terminal and a' negative polar# 'acontrol'grid meansfor supplying a direct voltage ity terminal, an impedance elementconnecting said anode ducting device shunted across said third resistorelement,

tron discharge device having ananode, a cathode and,l

a control grid, means connectingtheanode of said-seo ond' dischargedevice to said common pointya third resistor connecting the anode ofsaid'seconddischarge device to said positive polarity terminal, a secondpoten-- tiometer connected between said positive and negative `polarityterminals; said second potentiometer having a 'connected to thegridofsaid sccond discharge device,a fourth're'sistorconnected tosaid ineaiisfor `applying v grid maintaining' said discharge device atfanodecurrent a negative biasing potential to said cutoi for a predeterminedtime interval, said means comprising a` capacitor having one terminalthereof connected tosaid positive terminal through said first resistor`eleineritand having thegsecond terminal thereof -con nectedto saidnegative terminal through said second and third; resistor elementsconnected fin 'sei-ies, means for connecting the ji'inctionfofsaid4capacitor and said third resistor element ,to said control grid,and'switching `means connected between said negative terminal and thejuncl non of said capacitor and said first resistor element, saidpositive polarity terminaha second capacitor-.tor applyf ing a negativelbiasingfpotential to-the grid of said seci ond discharge deviceIconnected in series between said i -foui'th resistor and said grids-ofsaid second discharge device,

means connecting a point. in said series connection common to saidfourthresistor andsaid second capacitor -to the cathode of a thirdelectron discharge cathode .and a control grid,

device having an anode, a means connecting the anode said Seconddischarge device,

capacitor and the second and third resistor elements'having values atwhich the capacitor discharge time is substantially equal to saidpredetermined time interval.

`References Cited in the file ofthis patent UNITED STATES PATENTS tLivingston Dec. 28, `1943 t 2,368,477V Kinsman .jJan. 30, 1945 2,536,022Beach et al. Jan. 2, 1951 'i 2,735,007 McCurdy Feb. 14, 1956 Janssen etal. Feb. 17, 1959 a' third output voltage ,fromv from' the anode ofpolarity terminal, a tirst resistor elemenh 4'a `potentiometerconnectedv between said positive and negative terminals and comprising asecond resistor elementga third resistor element, Va `unidirectionallycon`

